Support bracket for an antenna balun box



FIG. 1 is a front, bottom, left side perspective view of a support bracket for an antenna balun box showing my new design;

FIG. 2 is a rear elevational view thereof, the front elevational view being identical to FIG. 2;

FIG. 3 is a right side elevational view thereof, the left side being identical to FIG. 3;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a support bracket for an antenna balun box, as shown and described. 